7HZ Eternal IEM Review






7HZ Eternal IEM Review




7HZ is a Chinese brand that has been established in 2012, which is located in Qingdao which is a province in Mainland China. However since their products have been mainly sold in China, the brand didn’t get our attention till the release of the Timeless, a Universal IEM with a 14.2mm diameter large Miniature Planar Magnetic Driver. Other products that have been released before the Timeless are the i77, i88/i88 Mini, i99 IEM’s and the Beatles Earbud.

The Eternal is the new latest Universal IEM of the company that was released to celebrate the 10th Anniversary of the company. The Eternal features a special designed Single Dynamic with a 14.5mm diameter LCD (Liquid Crystal Polymer) Diaphragm that is located inside a CNC Machined Aluminum Alloy Monitor Shell that sports a Sapphire Optical Glass Faceplate.





This sample has been provided to me for review purposes. I am not affiliated with any brand or person beyond this review and all these words reflect my true, unaltered and subjective opinions about the product.




Price & Availability:

The actual price of the 7HZ Eternal Universal IEM is 249.00 US$. More information’s can be found under the links below;




Package and Accessories:

The 7HZ Eternal came inside rectangular turquoise blue box that was wrapped with a glossy cardboard sleeve that sports the illustration of the Eternal and some product related banding.


Inside the box are the following contents/accessories; 

  • 1 pair x 7HZ Eternal Universal IEM
  • 1 pcs x Detachable Cable with MMCX Connectors
  • 4 pairs x Semi Transparent (Spinfit like) Silicone Ear Tips
  • 3 pairs x Silicone Ear Tips with large opening (S, M & L)
  • 3 pairs x Blue Silicone Ear Tips with small opening (S, M & L)
  • 1 pcs x Metal Protective Case
  • 1 pcs x Print Material (Quick Start Guide, Warranty Card, etc.)


The protective case of the 7HZ Eternal is made from a solid piece of metal (looks like aluminum material), which looks very robust and elegant.

The case has a nice textured surface that features an anodized finish in brown color. The protective case sports a very strong magnetic closure system that protects against unwanted openings.

On the top corner of the case is the 7HZ brand logo that looks quite fancy.




Design, Fit and Build Quality:

The 7HZ Eternal is a very robust looking In-Ear Monitor with a pretty unique design language. It is equipped with a 14.5mm diameter special LCP (Liquid Crystal Polymer) Diaphragm Dynamic Driver that is located inside CNC machined Aluminum Alloy cavity.

The housing is made from CNC machined Aluminum Alloy material that has a brown anodized fish.

On the front of the monitor shell is the Sapphire Optical Glass faceplate with a circular shape that looks pretty stylish.

The sapphire glass is a material used for high-end watches that has a coating, which is tempered to withstand scratches.

The sapphire glass faceplate has a nice blue tint that can be seen from different angles. Under the glass is a surface that has a design, which seems to be inspired by a camera lens aperture. This design looks pretty fancy especially under special light conditions.

At the rear side of the monitor is a angled sound nozzle with a stylish looking metal mesh on the top, which is on the front to a filter that prevents the insertion of particles such like dust or earwax.

Near the sound nozzle is a small vent to balance the pressure inside the monitor. Hear are also 3 additional openings and the L (Left) & R (Right) markings.

On the top of the monitor housing is the MMCX female connector that offers a tight and sturdy connection with the male connector on the detachable cable.

The overall build quality of the monitors is very good, which doesn’t show the smallest gap or visible imperfection.



Detachable Cable:

The 7HZ Eternal comes with a High-Purity OCC (Ohno Continuous Cast) + Single Crystal Silver wire detachable cable that features PVC insulation in brown color. The cable has a braided design and shows a low amount of microphonic effect.

The MMCX (Micro Miniature Coaxial) connectors do have a stylish protective housings made from plastic & metal material (brow) with a slightly curved design that do have L (Left) and R (Right) markings on the top.

Near the connectors are transparent PVC heat-shrink ear guides that are useful for a comfortable over the ear wearing experience.

The cable sports a chin slider and y-splitter made from metal material. The chin slider is in silver, while the y-splitter that sports the 7HZ branding shows a combination of brown and silver colors.

The detachable cable of the 7HZ Eternal is available with a 3.5mm Single Ended (TRS), 2.5mm Balanced (TRRS) and 4.4mm Balanced TRRRS) headphone plug options that you can chose on your purchase.

The headphone plug comes with the same stylish metal housing design like the chin slider and has the 7HZ branding on the top.  It has sports a transparent plastic strain relief for extra durability. I do like the cable that looks pretty durable and that doesn’t show any unwanted mixings.




Fit, Comfort & Isolation:

The 7HZ Eternal is maybe not the smallest Universal IEM on the market due to the circular shaped faceplate area that looks a bit large. However, the main body itself fits quite comfortably in to my ears with an average ear concha. I didn’t have had any comfort issues even after longer listening periods.

The passive noise isolation of 7HZ Eternal is on a moderate level, which are efficient enough for the use in fairly noise environments such like public transportations including bus, metro, or trains.




Some Technical Specifications:

  • Model                          : Eternal
  • Driver  Configuration  : 14.5mm Dia. Single Dynamic Driver with LCP Diaphragm
  • Frequency Range      : 10 Hz – 20 kHz
  • THD                            : <0.2%/1kHz
  • Sensitivity                   : 109dB/1kHz
  • Impedance                  : 30Ω
  • Connector                   : MMCX
  • Cable Specs               : 8 Core Silver Plated Single Crystal Copper Wire
  • Cable length               : 1.2m
  • Weight                        : 6 grams (single earpiece)





Pairing & Drivability:

The 7HZ Eternal has an impedance of 30Ω and a sensitivity of 109dB, which makes it to a relative easy to handle IEM. Sources with relative weak amplification such as Mobile Phones, regular Headphone Adaptors and Tablets are able to driver the Eternal to fairly high volume levels. However it truly shines when you pair it with more powerful sources such like DAP’s (HiBy RS6, iBasso DX240) or DAC/Amplifier (iFi Audio xDSD Gryphon).




Equipment’s used for this review:

  • IEM’s              : 7HZ Eternal, Meze Audio RAI Solo, Campfire Audio Honeydew
  • DAP&DAC’s   : HiBy RS6, iBasso DX240, iFi Audio xDSD Gryphon




Albums & tracks used for this review:

  • Adele – My Little Love (Spotify)
  • Randy Crawford – On Day I Will Fly Away (Flac 16bit/44.1kHz)
  • Hayley Westenra – Odyssey Album (Dezzer HiFi)
  • Dionne Warwick – Walk On By (Flac 16bit/44.1kHz)
  • Sarah McLachlan – Angel (Flac 24bit/48kHz)
  • Sertap Erener – Aşk (Flac 16bit/44.1kHz)
  • Edith Piaf – Non Je Ne Regrette Rien (Flac 16bit/44.1kHz)
  • Diana Krall – So Wonderful (DSF)
  • Aretha Franklin – I Say A Little Payer (Flac 24bit/96kHz)
  • David Bowie – Heroes (Flac 24bit/192kHz)
  • Elton John – Rocket Man ((Flac 24bit/96kHz)
  • Barry White – Just The Way You Are (Flac 24bit/48kHz)
  • Isaac Hayes – Walk On By (Flac 16bit/44.1kHz)
  • Sting – Englishman in New York – (Flac 24bit/48kHz)
  • Eric Clapton – Wonderful Tonight (Flac 24bit/96kHz)
  • B.B. King – Riding With The King (Tidal Hi-Fi)
  • Dave Gahan – Kingdom (Tidal Hi-Fi)
  • U2 – Sunday Bloody Sunday (Flac 16bit/44.1kHz)
  • Bro Safari, UFO! – Drama (Deezer HiFi)
  • Armin Van Buuren – Vini Vici (Flac 16bit/44.1kHz)
  • Really Slow Motion – Deadwood (Deezer HiFi)
  • Jo Blankenburg – Meraki (Spotify)
  • Lorde – Royal (Flac 24bit/48kHz)
  • Toutant – Rebirth (Deezer HiFi)
  • Portishead – It Could Be Sweet (Spotify)
  • Charly Antolini – Duwadjuwandadu (Flac 24bit/192kHz)
  • Michael Jackson – Billie Jean (Flac 24bit/192kHz)
  • Ferit Odman – Look, Stop & Listen (Flac 24bit/192kHz)
  • Chopin – Nocturn No. 20 In C-Sharp Minor (Flac 16bit/44.1kHz)
  • Fazıl Say – Nazım Oratoryosu (Live) (Flac 16bit/44.1kHz)
  • Vivaldi – Le QuarttroStagioni “The Four Season” (Deezer HiFi)
  • Otto Liebert& Luna Negra – The River (Flac 24bit/192kHz)
  • Lunatic Soul – The Passage (Flac 16bit/44.1kHz)
  • Deftones – My Own Summer (Shove it) (Flac 16bit/44.1kHz)
  • Metallica – Sad but True (Flac 24bit/96kHz)
  • Opeth – Windowpane (Flac 16bit/44.1kHz)
  • Megadeth – Sweating Bullets (Tidal Hi-Fi)
  • Rush’s – Leave That Thing Alone (Flac 16bit/44.1kHz)
  • Slayer – Angel of Death (Spotify)s
  • Liquid Tension Experiment 2 – Acid Rain (Spotify)
  • Yosi Horikawa – Bubbles (Spotify)





The Sound:

The first thing you will notice when you start listen to the Eternal is the pretty natural, clear and airy atmosphere, with a nice touch of warmness that is not overdone. The level of transparency and overall resolution form the lows up to the highs are impressive at this price point.

The lows are pretty controlled & clean, while the depth and intensity inn this area is on an efficient level with most genres. The midrange on the other hand sounds quite natural and realistic, while the treble region seems to be concentrated in the lower treble register that offers in general a good sense of clarity and definition, while the upper treble area shows an audible roll-off after the 8 kHz region.

This review has been written after a burn-in period of 60 Hours. I have used the 7HZ Eternal with Stock Semi Transparent Silicone Ear Tips and the stock cable that are included to the package. I have paired the Eternal with the iBasso DX240, HiBy RS6 and iFi Audio xDSD Gryphon.




The 7HZ Eternal come with a fairly natural and close to linear bass response that shows a sufficient level of depth and impact for most genres. However the bass performance that you will get at the end depends also quite a bit to the power (amplification) and character (tonality/coloration) of your source that you will use with the Eternal. The general bass characteristic of the Eternal makes it quite suitable with a wide variety of music genres including jazz, rock and electronic music.

The subbass region of the 7HZ Eternal is slightly less highlighted compared to its midbass are. It offers an adequate sense of depth and rumble, which doesn’t affects the clarity in this area in a negative manner. The feel of subbass rumble in songs like Lorde’s “Royals” or Massive Attack’s “Angle” is pretty entertain, but not on an ideal level for bass-head’s.

As I mentioned before, the midbass area is slightly more pronounced compared to the subbass region, it shows pretty natural tonality and sufficient level of body, depth and impact, when I do listen to acoustic guitars, violas or cellos, especially when paired with the HiBy RS6. Percussion instruments on the other hand like snare and kick drums are reproduced with a moderate grade of impact, while the speed and control on a good level.



The midrange of the 7HZ Eternal shows a decent sense of transparency and airiness, both in the lower midrange as well as the upper midrange area. The tonality of this region is a tad warmer than neutral that is created in the lower midrange register, while the timbre of instruments is quite natural. The general resolution of the midrange fulfills the expectation from an In-Ear Monitor at this price level.

The lower midrange created an average level of depth and body that could sound better if it would able to create just a bit more volume/intensity. Male vocals like Sting, David Bowie or Isaac Hayes do sound pretty clear and natural, while I would wish a bit more body. Instruments like strings or snare drums do have a moderate sense of depth and intensity while the grade of resolution and transparency is impressive.

The upper midrange of the 7HZ Eternal is more pronounced, detailed and energetic compared to the lower midrange area. Female vocals such like Adel, Edith Piaf, Diana Krall as well as Aretha Franklin do sound lively, emotional and detailed without to show any remarkable sibilance or harshness. The upper midrange is detailed, fairly energetic and offers a decent level of resolution and extension when I do listen to instruments like flutes, pianos or mandolins.

The 7HZ Eternal offers a decent midrange performance especially in the upper midrange register, which adds the overall presentation a nice sense of clarity and resolution, without to show remarkable weaknesses such like sibilance, dryness or over sharpens. My only complain could be come to the lower midrange area that could offer a bit more body and depth.



The 7HZ Eternal comes with a treble presentation that is moderately bright and fairly detailed. The focal point of the treble range is the lower treble register that shows an audible peak around the 5 kHz region, which is also visible in some frequency charts. The transitions from towards the lower treble area do sound in general pretty controlled; especially when instruments like electro guitars do play with high distortion.

The lower treble area is the more detailed part of the higher frequency region and offers a pretty good level of resolution and extension when I do listen to organs, pianos or soprano voices. The sense of clarity and definition fulfills my expectation from a product at this price tag, but is not breathtaking.

This upper treble region is mildly pronounced and shows a moderately peak around the 8 kHz region, which adds a sufficient sense of airiness and sparkle, when I do listen to instruments like hi-hats, cymbals and snare drums. The extension of instruments in this are is a bit short due to a fast and audible roll-off after the 8 kHz.

The treble range of the 7HZ Eternal offers in general a pretty good level of brightness and resolution, which is free of over sharpness or over saturation. This makes it ideal for those who are sensitive to treble sharpness and do look for something smooth and fatigue free.


Soundstage & Imaging:

The soundstage of the 7HZ Eternal offers a decent sense of transparency, where instrument and vocals are shown with a good level of separation. The soundstage has an above average wideness, while the depth of is on a moderate level.





Some Comparisons:


7HZ Eternal versus Meze Audio RAI Solo:

Both In-Ear Monitors do have a solid metal housing and do show a very esthetical look in their own way. The Meze Audio RAI Solo features a relative smaller 9.2mm diameter Dynamic Driver, while the 7HZ Eternal is equipped with a pretty large 14.5mm diameter Dynamic Driver.

When it comes to the sound I can say that the Meze Audio RAI Solo shows a slightly warmer tonality compared to the 7HZ Eternal. The general presentation of the 7HZ Eternal is more transparent and does offers a higher sense of resolution from the lows up to the highs.

The subbass region of the Eternal is slightly more highlighted and offers a better sense of depth, rumble and clarity, while both IEM’s are pretty similar when it comes to the level of control in this area. When it comes to the midbass region, I can say that the RAI Solo has the edge in terms of body and impact, while the Eternal is slightly better regarding the transparency and resolution.

The midrange of the Meze Audio RAI Solo has a slightly warmer compared to the 7HZ Eternal, which sounds a bit more natural and detailed in this area. The lower midrange of the RAI Solo offers a higher sense of body and depth, which makes it more musical when I do listen to male vocals and instruments like acoustic guitars and violas.

The upper midrange of the 7HZ Eternal sounds more natural and transparent with female voices and offer also a better level of extension and resolution when I do listen to instruments such like violins, pianos and flutes.

The lower treble region of the Meze Audio RAI Solo is slightly less highlighted and detailed compared to those of the 7HZ Eternal. The Eternal offers also a better sense of clarity and dynamism in this area. The Meze Audio RAI Solo on the other has the edge when it comes to the resolution and extension in the upper treble register, where it is also able to create a bit more airiness and sparkle.

When it comes to the soundstage performance, I can say that 7HZ Eternal is more successful in terms of airiness and wideness, while both IEM’s are pretty equal when it comes to the depth of the stage.



7HZ Eternal versus Campfire Audio Honeydew:

The Campfire Audio Honeydew features a relative smaller 10mm diameter Full Range Dynamic Driver (versus 14.5mm inside the Eternal) that is located inside a 3D printed monitor shell (versus Aluminum Alloy) that fit comfortable in to my ears

The Campfire Audio Honeydew shows a V shaped sound signature with focal point in the lows and highs. The tonality is noticeably warmer and the sense of coloration is quite high compared to the 7HZ Eternal, which offers a more natural and balanced presentation with less amount of coloration.

The subbass region of the Honeydew is more highlighted, which is the reason why it has more depth and rumble in this area, while the decay is slightly slower than does of the Eternal. However, the 7HZ Eternal offers a better level of authority, clarity and resolution in this region. The midbass region of the Campfire Audio Honeydew shows a higher grade of coloration; it has more intensity and sound more impactful, while the Eternal shows a more linear response with better sense of clarity and control.

The midrange of the Campfire Audio Honeydew is more recessed and shows a warmer tonality with higher grade of coloration compared to the 7HZ Eternal, which has a more forward oriented natural and balanced midrange tuning. The lower midrange of the Honeydew has more body and depth, which makes it more successful with male vocals, while it is transparent and detailed in this area.

Both the upper midrange and lower treble regions of the 7HZ Eternal do sound more pronounced compared to the Honeydew, which gives it an advantage in terms of detail retrieval and extension, when I do listen to instruments like a pianos or violin. The upper treble region is the area where the Campfire Audio Honeydew has the advantage, it shows a better sense of airiness and sparkle.

The soundstage of the 7HZ Eternal is more successful in terms of wideness, while the Campfire Audio Honeydew has a slightly advantage when it come to the depth of the stage.





The 7HZ Eternal is an eye catching In-Ear Monitor that will immediately impress you with its very robust craftsmanship and premium looking appearance. When it comes to the overall sound performance, I can say that the Eternal will easily satisfy when you are looking for a pair of IEM with a natural presentation, which should sound highly transparent, detailed and fatigue-free, even after longer listening periods.




Pros & Cons:

  • + Natural and Balanced Sound Profile
  • + Linear Bass Response with Good level of Clarity and Authority
  • + Transparent & Detailed Midrange Tuning
  • + Smooth & Natural Treble Character
  • + Eye Catching Monitor Design
  • + Very Robust Protective Case


  • – Audible Roll-Off in the Upper Treble Register
  • – Missing of some Lower Midrange Body & Depth
  • – Not the most suitable IEM for Bass Intensive Genres


Thank you for the Read!





You may also like...

2 Responses

  1. Fantastic review as always. I agree with your take on this set. That’s it just wanted to say good job.

Leave a Reply

Your email address will not be published. Required fields are marked *